Notes on soil ciliates from Singapore, with description of Suturothrix monoarmata nov. gen., nov. spec. (Protozoa, Ciliophora).

Few data are available on soil ciliates from Asia. Thus, seven samples were collected in Singapore in February 1987 and investigated between December 1987 and May 1989, using the non-flooded Petri dish method, live observation, and silver impregnation. One hundred and three ciliate taxa, all new for the fauna of Singapore and Malaysia, were found. This applies also to Hemimastix amphikineta, a highly characteristic, euglenid flagellate with Gondwanan distribution. At least three undescribed ciliate species were discovered, viz., Ottowphrya magna, which has been published by Foissner (1993), Dileptus microstoma Vd'ačný & Foissner (2008), and Suturothrix monoarmata, which is described in the present paper. The new genus Suturothrix belongs to the order Haptorida and is unique in having a heteromorphic dorsal brush consisting of three staggered rows, thus forming a suture with the last right side ciliary row. Suturothrix monoarmata is a slender, middle-sized (~ 100 × 15 μm) ciliate easily recognisable by the single or two thick extrusomes in the centre of the minute oral bulge. The species is not restricted to Asia but has been found also in soil from the Amazon floodplain, Brazil.